Hydrogen Sulfide?

Yes, I used the search engine, and yes, I have been to Gary's site.
And yes, I'm still confused.

My well was just completed today, and as expected, the driller reported high levels of hydrogen sulfide odor from the water extracted once he finally hit the mother lode (after penetrating 125' of limestone)....
he said the last well he drilled that was so stinky tested at 30ppm H2S...that's subjective, of course.

Neighbors told me to expect this, as they all have it. Walk into their homes, and it smells like the whole family does nothing but fart 24/7...

Two water-testing labs told me not to waste my money trying to test a sample for at least a month after the well was completed. BTW, water was not hit until 125', but yield was finally 20+ gpm, and within an hour the static level was about 3' below ground level...

My research initially pointed me toward a direct well chlorine pellet-drop system, but I have since read comments here and other places suggesting that chlorine in the casing is not generally a good idea, causing pump, wiring, pipe, etc. failures... Pellet-drop systems such as:http://www.betterwaterind.com/Chlorinator.html

So, will I be better off with a greensand filter? Maybe needing cascaded ones to handle the expected high ppm concentration?

I have read many comments about aeration, but most seem to involve atmospheric-vented tanks and a secondary submersible pump...which equals very redundant and expensive.

One thought I had was whether the aeration could be accomplished within the well casing itself...basically, a compressor, hose/pipe to bottom of well, to an airstone/bubbler, to disburse the disolved H2S? Or, would that cause aditional problems? [At this point, I know not what the iron situation if/will be].

I appreciate hearing from you. What you suggest is to knock out the H2S with chlorine (taking any iron with it), then removing the chlorine and residual odors/tastes with a carbon filter...it looks like a system such as you sell would be $1000+?

Is manganese greensand out of the picture due my assumed high H2S ppm levels?

Also, would like to hear from you (or, anybody) regarding the feasibility of in-well aeration...if that could work, it would seemingly be the cheapest, least intrusive way of mitigating hydrogen sulfide gas.

I'm also interested in hearing about quantifying the H2s...I'm hearing that it's fairly difficult to measure accurately to determine the ppm (or, mg/L).

You say that the well was just finished the other day...
Has that well been run at say 5gpm for 48-72 hours with out stopping?
Drillers around here do that and say that new wells often need some time of hard running to clear some things out from the new hole in to the water table.

Depending on what else is in the water, iron , manganese there are some other ways... and it depends on the flow rate from the well as to what media can or can not be used.

I agree with Gary. Chlorine is a lot cheaper than Kmn04, but I don't like using the pellet feeders. There are 2 small ports that get plugged with calcuim. Depending on the amount of hardness, I have had to clean this ports as much as every 3 months. As far as aeration into an open tank, it makes the air smell, the sprayers clog up and, like you said, it's being redundant. I don't know about pumping air into the well, so no comment there.

My further research suggests that any H2S exceeding 6ppm or so is best treated with chlorine rather than via aeration or greensand media...although not yet tested, my well water will definitely be way above 6mg/L, possibly ten times that amount!

So, I believe I will go with Gary's original suggestion, possibly substituting a liquid injector for the the dry-erosion one...that requires more research and/or an explanation from Gary. I'm familiar with liquid feeders from my swimming pool years, so that may just be my bias, but another poster made negative comments about the tablet-erosion ones, also.

Also wondering...can the mixing and filtration tanks be installed horizontally? I will be dealing with a 3-foot crawlspace and prefer to keep this stuff out of the above-ground living space if possible.

Also, regarding the backwashable carbon filter...I assume that the backwash function is to get rid of solidified sulfur and iron products that are created from chlorination, and that the carbon itself removes the residual chlorine and possibly chloramines?
How often will the carbon media need to be replaced, and at what approximate cost? I realize that each situation will be different, but I'm just looking for a wild-ass guess...

BTW...I'm a new poster here, but have lurked for many years, and consider the advice here to be of better quality than found on most forums...

Karl in NY, I know from my own system that a Stenner chemical pump has worked well for me. You can adjust precisely how much chlorine enters the water stream. With a chlorine test and trial/error; you can add just enough to be "used up" by the H2S and leave little to no "free" chlorine to travel into your home. Certainly less chlorine than city water.

As was said by others; you will need to filter H2S/chlorine reaction particulate. As far as drinking water; a simple "at tap" carbon filter can assure your water is chlorine free.

Ksnakes: I'm interested in your setup. Can you post a picture? What type of feeder/injector? Do you use household (laundry) chlorine bleach? What do you use to filter the precipitated sulfide/iron?

I have 2.6 ppm iron and rotten egg smell in cold & hot water (not just at beginning of the day). The 14-year old Culligan Mark 89 water softener (which I have reconditioned with Sears water softener product--which appears to be the same stuff as Pro Solutions Rust-Out) adequately softens the 24 grain hardness water, recharging @ 10 lbs salt every 3 days (timer). I tested the softened water, and the iron has been removed as well.

I am curious how you:

(i) deal with the post-chlorination particulate (do you run it through a filter before water softener, or rely on the water softener to filter/backwash?);
(ii) assure there is no left over chlorine at the kitchen/bath tap/shower;

Also, what is considered "medium" hydrogen sulfide? Did you have the water tested? Thanks, and sorry for all the questions.

Gary: At that last link in your post, it says: "[the dry chlorination] UNITS MUST BE INSTALLED AFTER PRESSURE TANK." Why is this? Is it because:

(i) Chlorine would damage the butyl or vinyl in the tank?
(ii) Chlorine injected ahead of the tank would cause iron, maganese, and sulfer particulates to gum up the tank or pressure regulator?
(iii) Chlorine injected ahead of the tank would cause iron, etc., particulates that sit in the tank to form a breeding ground for iron bacteria overnight?
(iv) There is something about the engineering or physics of the dry chlorine pellet unit that requires its installation after the tank?
(v) Other?

Since contact time is an issue for chlorine to be effective, I would think (all else being equal) that the closer to the well head the chlorine is injected, the better. And, barring other problems, if the chlorine is injected before the pressure tank, the pressure tank would help increase contact time. Finally, if coliform bacteria ever does make it into the well, then chlorine injected ahead of the tank would help sanitize the tank, would it not?

Related question:

Is there a good argument to be made for installing an activated carbon filter (e.g., Centaur) AFTER the water softener? It seems to me that carbon filter media (especially Centaur) is more expensive and lasts much few years than cheaper, high quality softener resin (which is ubiquitous). So, if the chlorine injection cannot take place ahead of the tank, why not place it AFTER the softener (although I realize that this might require installation of a mixing tank to increase contact time)? That way, the softener could do the heavy lifting of removing the iron (2.6 ppm in my case), and less chlorine/filtration would need to occur at the carbon filter. My back washes on that filter could be set more infrequently--saving water, electricity, and filter media lifespan over the long run, would it not?

It goes after the pressure tank for a number of reasons, one is because you don't want to damage the pressure tank. With correctly sized retention, I used a mixing tank equal to a 120 gal retention tank, you don't need to use the pressure tank. You kill bacteria before you use the water, so you don't need to kill it at the well.

You clean the pellet hopper every 2-3 months and add new pellets. It's like checking tire pressure, if you don't do it on a schedule you pay the consequence of wearing out tires, poor fuel mileage etc..

Maintenance on a solution feeder can be much more and 'iffy' as to them working correctly no matter what you do with them. I refused to sell solution feeders since back in the 1990s.

Anyone injecting chlorine and not removing it is running a risk of creating health problems unless they are constantly testing for chlorine and limiting it to .2-1.5 ppm, which is still too much in my opinion but what water companies are allowed.

Centaur in a correctly sized for the peak demand (SFR) backwashed filter is best for particulate and chlorine removal after chlorine injection. Softener resin does not remove either very well and doing so will ruin any resin.